Kid's Health

Time to Change

OK, so it's a funny word — but what is puberty, anyway?

Puberty (say: pyoo-ber-tee) is the name for the time when your body begins to develop and change as you move from kid to adult. We're talking about stuff like girls developing breasts and boys starting to look more like men. During puberty, your body will grow faster than at any other time in your life, except for when you were a baby.

It helps to know about the changes that puberty causes before they happen. That way, you know what to expect. It's also important to remember that everybody goes through these changes. No matter where you live, whether you're a boy or a girl, whether you like vanilla or double-fudge-chunk ice cream, you will experience them. No two people are exactly alike, but one thing everyone has in common is that we all go through puberty.

Usually, puberty starts between ages 8 and 13 in girls and ages 10 and 15 in boys. This wide range in ages may help explain why some of your friends still look like young kids whereas others look more like adults.

When your body is ready to begin puberty, your pituitary (say: pih-too-uh-ter-ee) gland (a pea-shaped gland located at the bottom of your brain) releases special hormones. Depending on whether you're a boy or a girl, these hormones go to work on different parts of the body.

Changes for Boys and Girls

For boys, the hormones travel through the blood and tell the testes (say: tes-teez), the two egg-shaped glands in the scrotum (the sac that hangs under the penis), to begin making testosterone (say: tess-tahs-tuh-rone) and sperm. Testosterone is the hormone that causes most of the changes in a boy's body during puberty, and men need sperm to be able to reproduce (be the father of a baby).

In girls, these hormones target the two ovaries (say: o-vuh-reez), which contain eggs that have been in the girl's body since she was born. The hormones cause the ovaries to start making another hormone, called estrogen. Together, these hormones prepare a girl's body to start her periods and be able to become pregnant someday.

Boys and girls both begin to grow hair under their arms and their pubic areas (on and around the genitals). It starts out looking light and thin. Then, as kids go through puberty, it becomes longer, thicker, heavier, curlier, and darker. Eventually, boys also start to grow hair on their faces.

It's Just a Growth Spurt

A spurt is a short burst of activity or something that happens in a hurry. And a growth spurt is just that: Your body is growing and it's happening really fast!

When you go through puberty, it might seem like your sleeves are always getting shorter and your pants are creeping up your legs. That's because you're having a growth spurt that lasts for about 2 to 3 years. When that growth spurt is at its peak, some kids grow 4 or more inches (10 or more centimeters) in a year! At the end of your growth spurt, you'll have reached your adult height — or just about.

But your height isn't the only thing that changes during puberty.

With all this quick growth, it can seem like one part of your body — your feet, for instance — are growing faster than everything else. This can make you feel clumsy or awkward. This is normal, too! The rest of your body will eventually fill out and shape up, and you'll feel less klutzy.

Taking Shape

Your body also fills out and changes shape during puberty. A boy's shoulders will grow wider and his body will become more muscular. He may notice a bit of breast growth on his chest. Don't worry, this is normal — and it goes away for most boys by the end of puberty.

In addition, boys' voices crack and eventually become deeper, their penises grow longer and wider, and their testes get bigger. All of these changes mean that their bodies are developing as they should during puberty.

Girls' bodies usually become curvier. Their hips get wider and their breasts develop, starting with just a little swelling under the nipples. Sometimes one breast grows more quickly than the other, but most of the time they even out. Girls may start wearing bras around this time, especially if they are involved in sports or exercise classes.

With all this growing and developing going on, some girls may be uncomfortable with how their bodies are changing, but it's unhealthy for girls to diet to try to stop any normal weight gain. If you have any questions about puberty or are worried about your weight, talk to your parent or doctor.

One question a girl will have is: When will I get my first period? This usually happens about 2 years after her breasts start to develop. The menstrual (say: men-strul) period, or monthly cycle, is when blood is released through the vagina. That may sound alarming, but it's normal and it signals that a girl is growing up and her body is preparing so that she can have a baby someday.

Here's what's going on: Each of a girl's two ovaries holds thousands of eggs. During the menstrual cycle, an egg is released from one of the ovaries and begins a trip down the fallopian (say: fuh-lo-pee-un) tube to the uterus, also called the womb. A girl has two fallopian tubes, one connecting each ovary to the uterus.

Before the egg even leaves the ovary, though, hormones stimulate the uterus to build up its inner lining with extra blood and tissue. If the egg gets to the uterus and is fertilized by a sperm cell, it may plant itself in that lining and grow into a baby. The extra blood and tissue nourishes and protects the baby as it develops.

But most of the time the egg is only passing through. When the egg doesn't get fertilized, or if the fertilized egg doesn't become planted in the lining, the uterus no longer needs the extra blood and tissue, so the blood leaves the body through the vagina. This blood is known as a girl's period. A period usually lasts from 2 to 7 days. About 2 weeks after the last period, a new egg is released as the cycle repeats itself.